水电站直埋蜗壳结构受力特性与承载力

基于损伤理论，采用ABAQUS程序对某大型水电站直埋蜗壳方案进行非线性有限元计算，实现了蜗壳加载过程及超载的数值仿真，研究了此新型结构在内水压力上升的过程中钢蜗壳和钢筋应力、混凝土开裂区和机墩上抬位移的变化规律以及结构的超载能力．结果表明：当荷载达到0．5倍的设计内水压力时，蜗壳外围混凝土将进入开裂阶段，钢蜗壳和钢筋应力变化加快，机墩上抬位移变化速率也增加；但是在设计荷载作用下直埋蜗壳的整体安全度仍然很高，其内水压力的超载安全系数在2．0以上．这种蜗壳结构型式应用于实际工程是完全可行的．

Mechanical Characteristics and Bearing Capacity of Complete Bearing Spiral Case in Hydropower Station

By means of the ABAQUS software, a nonlinear finite element method （FEM） based on damage theory was used in structural calculations of the complete beating spiral case of a large-scale hydropower station. The simulation of loading and overloading process has been realized to study the regularity of the stress changes in steel lining and reinforcing bar with the rise of the internal water pressure, propagation of the crack range in concrete and the rise of generator pier as well as the overload capacity of the new structure. It is concluded that the concrete around spiral case will crack and the stress increasing rate of steel lining and reinforcing bar as well as the rising rate of generator pier will increase obviously when the internal water pressure reaches half times of design value. However, the complete beating spiral case still has enough integral safety under the design loads, and the overload safety factor of the structure could be more than 2.0. So it is advantageous and feasible to be applied in the practical projects whether from the aspects of structure or economy and technique of construction.